As a conventional disk apparatus, there is an apparatus provided with a radial adjustment section and a tangential adjustment section on a base unit chassis of a stator base of a spindle motor, with the object of making possible high-precision skew adjustment by means of a simple configuration.
Skew adjustment in this conventional apparatus is performed in the following way (see Patent Literature 1, for example). First, an optical pickup is moved to the skew adjustment fulcrum side of a pickup sub guide shaft. Then radial-direction and tangential-direction skew adjustment is performed by the radial adjustment section and tangential adjustment section so as to optimize the value of jitter and the like. Next, the optical pickup is moved to the skew adjustment section side of the pickup sub guide shaft. Then tangential-direction skew adjustment is performed by the pickup sub guide shaft adjustment section so as to optimize the value of jitter and the like.
Here, the radial direction is the direction of the normal to a signal track of the disk in the relationship between the optical pickup and disk signal surface, and the tangential direction is the direction of the tangent to a signal track of the disk. Also, the difference in the tangential angle when the optical pickup is positioned at the inner periphery and when the optical pickup is positioned at the outer periphery is referred to below as residual tangential tilt.
That is to say, with a conventional apparatus, it is possible to perform tilt adjustment in two directions—the radial direction and tangential direction—so that the disk signal surface and the optical axis of the optical pickup are orthogonal, and it is also possible to adjust residual tangential tilt.
Citation List
Patent Literature
    PTL 1    Japanese Patent Application Laid-Open No. 2005-63549